2. What is wireless power transmission(WPT)?
Why is WPT?
History of WPT
Types of WPT
› Techniques to transfer energy wirelessly
Advantages and disadvantages
3. The transmission of energy from one place to
another without using wires.
Conventional energy transfer is using wires.
But, the wireless transmission is made
possible by using various technologies.
4. As per studies, most electrical energy transfer
is through wires.
Most of the energy loss is during
• On an average, more than 30%.
• In India, it exceeds 40%.
6. Nikola Tesla in late 1890s.
His vision for “World Wireless System”.
The 187 feet tall tower to broadcast energy.
All people can have access to free energy.
Shortage of fund lead to no operation.
He used to lamp 200 lights from 40 km distance
8. The transfer of energy
› Magnetic coupling
› Inductive coupling
Simplest Wireless Energy
coupling is a transformer
9. Primary and secondary
coils are not connected
Energy transfer is due to
Brushes are some
10. The capacitor and inductor forms the
resonator. Charge oscillates between
inductor (as magnetic field) and
capacitor (as electric field.)
This type of oscillation is called
resonance if the reactance's
of the inductor and capacitor
11. Coil provides the inductance.
Capacitor is connected parallel
to the coil.
Energy will be shifting back and
forth between magnetic field
surrounding the coil and electric
field around the capacitor.
Radiation loss will be negligible
12. Toughest technique under near-
field energy transfer techniques
Air ionizes only when there is a
Needed field is 2.11MV/m
Natural example: Lightening
Not feasible for practical
No wire, No e-waste
Need for battery eliminated
Efficient & Harmless
Field should be under safety level
High initial cost
Tuning is difficult in RIC
14. LASER is highly directional, coherent.
Not dispersed for very long.
But, gets attenuated when it propagates through
› Photovoltaic cell.
15. To efficiently make use of renewable
energy i.e., solar energy.
SPS are placed in geostationary
Each SPS may have 400 million
Efficiency exceeds 95%
if microwave is used.
Efficient , Easy
Need for grid eliminated
Low maintenance cost
More effective when the
transmitting and receiving points
are along a line-of-sight
Can reach the places which are
When LASERs are used,
› conversion is inefficient
› Absorption loss is high
When microwaves are used,
› interference may arise
17. Qi(Chee) is a interface
Developed by Wireless
It works for a distance up to
Comprises a transmission
pad & a compatible receiver
18. Near-field energy transfer
› Electric automobile
Static and moving
› Consumer electronics
› Industrial purposes
19. › Far-field energy transfer
Solar Power Satellites
Energy to remote areas
Can broadcast energy
globally (in future)
20. Transmission without wires- a reality.
Efficient & Low loss.
Low maintenance cost. But, high initial cost.
Better than conventional wired transfer.
Energy crisis can be decreased.
In near future, world will be completely